A team of environmentalists and archaeologists from the state University of Mato Grosso in Brazil and the University of Exeter in the UK found in the Amazon river basin a large number of abandoned dark earths. The analysis showed that it was a field in which people applied fertilizers 5,000 years ago.
A study published in the journal Global Ecology and Biogeography, and briefly about it it is told on the website of the University of Exeter. Scientists conducted a study whose purpose was to identify the role of ancient farmers in shaping the modern landscape of the Amazon.
They drew attention to the fact that along the Amazon river there are many forest areas, which by their species composition differ significantly from the surrounding areas.
Scientists have discovered thousands of such sites, most of which were the size of a small field. They conducted excavations, which showed that at these sites the top layer of soil, in contrast to relict forests, is very dark, almost black.
In addition, these soil layers were found the remains of charcoal and ceramics. These samples are examined in laboratories. The age of some of them is about 5000 years. Also, researchers studied about 4,000 trees that grow in the dark lands, and near them, on a regular basis. It turned out that the dark lands dominated by trees whose fruit can be eaten.
All this has led researchers to the conclusion that dark earth was artificially created by man. Charcoal, ceramics and other fertilizers thousands of years were intentionally introduced into the soil. This helped to create a diverse ecosystem with a rich set of plant species.
Dark lands stretch for a thousand kilometers. Not yet established exactly who created them, and when they were abandoned. Research has proven that dark land people don’t use for a long time.
"Creating a dark land, the early inhabitants of the Amazon were able to successfully work the soil for thousands of years, says Professor josé Iriarte, an archaeologist from the University of Exeter.- We think that ancient communities used dark earth for the cultivation of grain, and the adjacent forests to the dark lands for agroforestry."